A watch case corresponding to the generic definition just given above is known from various prior documents.
In the patent document GB-A-102 641 the case is provided with a cap covering the caseband and including two loops. The cap is secured to the remainder of the case by fixing the strands of the bracelet in these loops. The drawbacks which such cases exhibit render them rather unattractive. Effectively, since the cap is not rigidly secured, it may readily be displaced on the caseband. Furthermore, the risk of having the cap torn off cannot be entirely eliminated.
The patent CH-A-558 040 describes a watch case including a protective cap of extra hard material. In this construction the cap is maintained in place by screws which are perpendicular to the plane of the case and which traverse the caseband-bezel and are retained in threaded studs attached under the cap. Here the cap exhibits a rather complex cross-section in view of these threaded studs. The caseband-bezel must be given a special form in order to be adapted to the cap which covers it.
Patent CH-A-517 963 (=US-A-3 242 664) describes a watch case including a caseband-bezel of steel surmounted by a cap formed of metallic carbide. Caseband and cap are fastened to one another by force fitting. The description in the patent at the same time mentions that in order to compensate for eventual variations in the dimensions of the cap it is preferable to glue the cap onto the caseband, the layer of glue thereby compensating any lack of precision.
Patent CH-A-307 046 suggests a cap of transparent plastic material covering the case, itself made of plastic material. The underside of the cap is covered by metallization the thickness of which may be very small (between 0.5 and 1 .mu.m) since protected by the cap. The cap thus coated is glued to the case. In addition to the fact that this is a difficult construction, it will be noted that the outer portions of the cap made of soft material are subject to rapid deterioration (scratches, etc.).
To applicant's knowledge, it has never been proposed to cover a caseband-bezel of plastic material with a metallic cap and still less to glue these pieces to one another. The gluing of plastic material onto metal has long suffered and continues to suffer from unfavourable prejudices, leading to avoidance thereof as much as possible and being replaced by mechanical means judged safer and more reliable such for instance as the employment of screws or hooking devices. It is true that the caps known to the present time are heavy and massive and proof thereof may readily be seen in the drawings illustrating the cited documents. In view of their mass, such caps could readily be detached from a caseband made of plastic if they were simply glued thereto. However, if the cap is light, made from a blanked and drawn leaf and if furthermore one is able to choose judiciously the materials to be glued and the glue itself, the applicant has discovered that securing the cap by gluing it to the caseband is very satisfactory vis-a-vis the forces and stresses which are produced during wearing of the watch.